Now, aside from Type designations, PFDs are available in either the traditional foam format or inflatable PFDs. Standard PFDs tend to be less expensive, lower maintenance, naturally buoyant and extremely versatile. However, they can be hot and bulky when paddling and fishing.
Inflatable PFDs, on the other hand, are inflated either manually via a cord or automatically when submerged in water. Inflatable PFDs are more comfortable, low-profile and help the wearer stay cool, but they must be inflated to work. These types of devices require maintenance and CO2 cartridges to inflate, making them significantly more expensive to purchase.
There are also hybrid versions that provide the best of both worlds, but they also cost more than the traditional life vests.